The single most important component of an NMR spectrometer is the probe which holds the sample in the center of the magnetic field. It consists of a coil tuned to the pertinent resonance frequencies and the associated mechanical components for the assembly including temperature control. The largest improvements in the experiments are gained through development of the probes. Most of the effort is devoted to the development of probes optimized for membrane protein samples, in particular flat-coil probes for samples oriented between glass plates. This involves the refinement of existing designs and the development of new designs for operation in the new high field spectrometer. In addition to improved rf performance, advances in temperature and humidity stabilization are being made, which are important factors in the success of studies of membrane proteins.